1. Field of the Invention
The present invention is generally directed to the field of systems and methods for securing fluid sealing devices that prevent fluid leakage in mechanical systems. More specifically, the present invention is directed to improved systems and methods for installing ring-shaped seal members and specific embodiments of the invention provide the ability to maintain the orientation of seal members during insertion.
2. Description of the Related Art
A wide variety of ring-shaped seal members have been used in mechanical systems in order to prevent the leakage of fluids in these systems. They are typically utilized in the field of hydraulic drive systems in order to prevent fluid leakage in the mechanical systems driven by the hydraulics. There are currently a wide variety of seal members available today from simple O-ring single component seal members to scarf cut seals as well as more complex composite seals made from unitary bodies of material. More recently, composite ring-shaped seal structures have been introduced which have improved fluid leakage prevention characteristics over existing conventional seals. Unfortunately, one of the drawbacks of these new and improved sealing structures is that the existing conventional systems and methods for applying conventional seal structures in their desired locations are inadequate for the new and improved composite seal structures.
For example, a typical conventional system and method for applying conventional O-ring seals is found in the fabrication of fuel injector components. In these prior art systems and methods, conventional O-ring seals of varying diameters are applied to a fuel injector component body. In order to accomplish seating of the seal member in a desired location, a machine is utilized to pneumatically drive or force the O-rings to a desired level on a fuel injector assembly. During this process, a pneumatic drive would push a circular tube with slits cut in the side of the tube at the distal end in order to allow radial expansion of the distal portions of the tube as the tube extends over an application tube that has a somewhat conical portion to allow the O-ring seal member to gradually expand over the application tube.
FIG. 1 illustrates an example of a prior art sealing application system and method wherein an O-ring seal is applied on a mechanical housing. As shown in the illustration, a mechanical body on which a seal is to be located 12 includes ridges 14,16 within which the O-ring 17 is to be secured. In order to facilitate placement of the O-ring at the desired location on the mechanical body, a conical insertion device 18 is placed over the mechanical body 12 to which the seal is to be applied. During the installation process, an O-ring seal 17 is placed over the conical body 18 and a tube 19 having a plurality of vertical slits in the distal end of the tube is then inserted over the conical member on which the O-ring seal member is located. The slits in the application tool allow the distal end of the tool to engage side wall of the O-ring seal member as the device is pushed downward over the conical member. During the application process, because force is applied from a side wall and the conical body on which the O-ring rests, the O-ring tends to roll as the ring is pushed downward along the conical member. Those skilled in the art will appreciate that in these prior art application systems, an automated machine that was typically, pneumatically driven, would be utilized to place the seal on the conical body and force the application tool downward to secure the seal in a desired location.
In this process, the distal end of the application tube is in contact with the seal member as the seal is pushed down along the sides of the fuel injectors. A mechanical stop interacts with the O-ring seating tube and prevents displacement of the O-ring beyond a desired point. This mechanical stop ensures that the seal member is secured at its desired location on the fuel injector component. Typically, there is a metallic ribbed portion on the device on which the seal is located that would secure the seal.
In these prior art systems and methods for installing rubber O-ring seals, there was previously no concern for rolling of the O-ring member while the O-ring was driven into position down the tapered or conical shaft of the insertion device. This was due to the fact that the characteristics of an O-ring sealing member are such that orientation of the seal is not particularly important in order to achieve the desired sealing effect.
Recently, specifically in the field of automatic transmission systems, new zero leak seals have been designed which are composite components that are comprised of layers of PTFE and FKM elastomer. These new zero leak seals are comprised of an outer PTFE ring-shaped body and a central inner ring secured to this outer PTFE body that is typically comprised of flexible material, such as, for example, FKM elastomer. In preferred embodiments of these sealing members the elastomer is configured to have various ridges on an inner portion of the zero leak seal member which further aid in the sealing characteristics of the product. In light of the specific characteristics of this product, it is imperative that the orientation of the seal member be maintained such that the inner portion of the seal is the flexible elastomeric portion and the outer portion is the PTFE body on which the elastomeric is secured.
If the zero leak seal member is allowed to roll during the application process to switch the orientation of the inner and outer portions, the seal will not work as intended and will fail. Accordingly, it was necessary to develop new manufacturing techniques for securing these new and improved zero leak sealed member bodies and mechanical assemblies.
The inventors of the present systems and methods for applying new zero leak seals attempted to utilize various versions of the prior art techniques for installing the new and improved zero leak seals without success. Previous attempts at solving this problem included providing various beveling on the distal ends of the insertion tube with the slits cut in the distal end in order to attempt to prevent rolling of the zero leak seal during the application process. As noted rolling of these new zero leak seals effectively destroys their ability to provide a sound fluid seal. Others have attempted to provide improved techniques which would result in the desired application of a zero leak seal member but have not succeeded in providing an acceptable solution.
Thus, there remains a need in the field for new and improved systems and methods for installing ring-shaped seal member bodies. Accordingly, one object and advantage of the present invention is to provide improved systems and methods for installing ring-shaped seal member bodies which can be utilized with zero leak seal members. Another object and advantage of the present invention is to provide improved systems and methods for installing ring-shaped seal member bodies which aid in preventing rolling of the ring-shaped seal member body. Other objects and advantages of the present invention will be apparent in light of the following Summary and Detailed Description of the Presently Preferred Embodiments.
In accordance with the present invention, new and improved systems and methods for installing ring-shaped seal member bodies are provided. In accordance with a first preferred exemplary embodiment of the present invention, the systems and methods for installing a ring-shaped seal member body on a mechanical housing include steps of placing a tapered insertion tool over the mechanical housing on which the ring-shaped seal member body is to be located and thereafter placing a ring-shaped seal member body on the tapered member.
In accordance with a preferred exemplary embodiment of the present invention, when the ring-shaped seal member body is a zero leak seal, the zero leak seal member body is placed on the tapered member with the rubber portion oriented toward the center of the tapered member. Orientation of the seal member in this manner prior to securing the seal ensures that the appropriate orientation for the ring-shaped seal member body is achieved on the mechanical body on which the seal member is to be placed.
After the seal member has been placed on the tapered insertion body, an insertion device is pushed downward over the tapered member. This insertion device is comprised of two separate portions at a distal end of the insertion tool. In accordance with the preferred exemplary embodiment, the inner member is the first to engage the ring-shaped seal member body as the insertion tool is lowered over the tapered body. The inner member is comprised of an elongated tube-shaped member with a plurality of slits cut in the distal portion to allow the distal end of the tube-shaped member body to readily expand over the sides of the tapered body during the insertion process. As the insertion tube slides over the tapered member, the tapered body engages the distal end of the insertion tube and gradually expands the outer diameter of the insertion tube. This is enabled by the vertical or lengthwise slits in the distal of the insertion tube. As the insertion tube gradually extends downward on the conical body, the distal end of the insertion tube engages the side of the zero leak seal member body. In accordance with the preferred exemplary embodiment, the distal end of the tube-shaped body which makes contact with the ring-shaped seal member has a beveled face such that an inner portion of the tube member gradually slopes away from the distal end. This beveled face is desirably placed at an angle that depends on the geometry of the seal members. The initial contact in the preferred embodiment occurs typically at the tip of the beveled end of the base and the side wall of the zero leak seal member body closest to a top of the tapered member. As the insertion device is further inserted downward over the conical member, the ring-shaped seal member body expands with increasing diameter of the tapered member. The contact between the side of the seal and beveled edge of the insertion tool aids in the prevention of rolling of the ring-shaped seal member body.
A further tubular member or second portion of the insertion device having a diameter greater than the tapered insertion device includes an inner wall in the preferred exemplary embodiment that has a substantial vertical wall at the distal end. This additional tubular body is located to ensure that the ring shaped seal member body does not roll as it expands along the tapered side wall of the tapered member. It is also preferably dimensioned such that the inner diameter of this member is preferably the diameter of the tapered member at its largest point plus ⅔ of the unstretched part thickness of the nominal unstretched seal thickness of the ring-shaped seal member body in its unstretched position. As detailed below, this tubular body has an inner wall that is slightly below the wall of the seal opposite the beveled wall of the insertion tube to prevent rolling of the seal during insertion. This physical relationship is preferred in order to ensure that this member does not pull back on the ring once it has set into its desired location.
The physical spatial relationship between the inner and outer tubular members or portions of the insertion tool is preferably maintained during the insertion process to be constant. A mechanical stop ensures that the inner tubular member extends only to the edge of the desired location of the ring during the insertion process. This edge is also the end of the tapered body and this physical relationship allows the ring-shaped seal member to snap into place at its desired location. In accordance with the preferred exemplary embodiment, multiple tapered or conical members are sequentially placed on a mechanical housing to which a plurality of seals are to be located and each of the separate tapered members is configured to end at each desired seal placement location. Accordingly, in accordance with the preferred exemplary embodiments of the present invention, a ring-shaped seal member body may be readily inserted such that the orientation of the inner and outer portions of the ring-shaped seal member body are maintained.
In accordance with the preferred exemplary embodiment, both the tapered member and the insertion tube members are comprised of stainless steel. The inner insertion tube member has slits cut into its body in order to allow the distal end to expand around the increasing diameter of the tapered member. Those skilled in the art will appreciate that other materials may be utilized for formation of the various devices utilized in the systems and methods of the present invention. In particular, plastic may be substituted for the preferred steel construction. Steel is preferred, however, because of the slip characteristics of this material which more readily allows sliding of the various components. Those skilled in the art will recognize that plastic or perhaps some other carbon or composite material may be utilized as well for formation of the tapered member as well as the insertion tool portions.
The insertion tool may actually be comprised of two distinct members or the two separate portions may be formed into a single device.